German Green MEP Ska Keller dismisses outright the notion that environmental and ecological questions should take a back seat to the economy as European leaders seek to put the financial crisis behind them.

Rather, the Green candidate for the presidency of the European Commission says sustainable investment is crucial both for job creation and the transformation of the environment.

“There are certainly political forces – conservatives – who would say certainly, economy first, nature comes later. But that is a completely wrong approach,” said Ms Keller.

“We are only going to get out of this crisis if we’re putting our economy on a sustainable field, if we invest in those renewables, energy efficiency, if we transform our economy.

“It was always believed that if the single market was running then everything else is also running but it’s not the case. We have now much less freedom for people and less security for people than for goods and capital.”

Ms Keller (31) is the youngest of the parliament's candidates for the commission's top post, but she readily accepts the Greens are unlikely to prevail.

On a rapid visit to Dublin, she was adamant that the very idea of having candidates for the commission presidency marked a big advance. “We think it’s been a great step forward in democracy to have that job open for candidates.”

The European Parliament has advocated that the candidate of the largest voting bloc in the parliament should lead the commission.

This puts Ms Keller in the same field as former Luxembourg premier Jean-Claude Juncker, candidate of the centre-right European Peoples' Party; German MEP Martin Schulz, for the Socialists; former Belgian prime minister Guy Verhofstadt of the liberal group; and Greek MP Alexis Tsipras of the Party of the European Left.

While it is far from clear that heads of state and government will accept that outcome, Ms Keller insisted it would be a travesty for EU leaders to overlook the outcome of the 28-country election this weekend.

“I think they simply cannot afford to ignore the will of the citizens. All of the member states have been signing up in supporting one or the other depending on their majority or government position,” she said.

It may ultimately boil down to a two-man contest between the two elder candidates, Mr Juncker and Mr Schulz, but their rivals do not see it that way. “Imagine you had only Schulz and Juncker talking, it would be so boring,” said Ms Keller.

Having joined the campaign trail in central Dublin yesterday with Green candidate Eamon Ryan, she was all too aware of his party's painful experience in power with Fianna Fáil.With polls suggesting Mr Ryan remains in contention for the third and final seat in Dublin, Ms Keller said every seat counted in the European assembly.

“We have very close votes sometimes, sometimes it’s a matter of one vote to get the Green agenda through.”